Which answer should I choose?

Don't hesitate to accept an answer that is well-written, suggests a good practice and works for you.

Otherwise, even if there are answers that are good enough but that you're not entirely satisfied by, you might wait 24 to 48 hours to give other people a chance to give you a better answer. A question with an accepted answer isn't as likely to receive further attention as one without an accepted answer.

Make sure that besides working for you, the answer is really good practice. Sometimes after the answer gets accepted, another comes in, uncovering the fact that previous one was in fact a bad hack.

The bottom line is that you should accept the answer that you found to be the most helpful to you, personally.

Upvote

If an answer has helped you solve your problem and you accept it you should also consider voting it up.

If other answers have been helpful too, you can also vote them up.

What should I do if none of the answers is suitable?

Re-read your question critically and make certain that it's clear what the problem is, and what the specific question is. You might want to place a bold single sentence version of your question at the bottom of your post to make sure it's clear what's being asked.

Re-read the answers. Consider accepting the best answer of the bunch, even if none of them are exactly what's needed.

Wait a few days after asking it, and then edit your question with what you've learned since asking it — perhaps additional information will help others help you. This will also have the effect of bringing your question back onto the home page where fresh eyes will see it.

If you have more than 75 reputation, you can add a bounty two days after the question is asked if you haven't accepted any answers yet. This will add incentive for people to answer your question.

Eventually you'll resolve the problem or find a work-around (which may be, "This won't work, so here's what I did instead"). Please add an answer with this information and accept your own answer so that others with your same question can see the path you eventually followed.